Oregon Episcopal School in Raleigh Hills is the top private high school in the state and 14th best in the country, according to a ratings report released this week by a Pittsburgh-company. It was the only school in the Oregon to be listed in the top 100.

The study, by consumer research site Niche.com, grades each school based on the academics, figures about diversity and survey responses. Released on Monday, the study gathered responses from more than 16,000 students, parents and recent alumni from across the nation and gave a numerical ranking to almost 4,000 schools.

According to Mark Tressler, vice president of business development, Niche was founded in 2002 as CollegeProwler.com. Started by Carnegie Mellon University students, College Prowler ranks colleges and universities based on reviews and recommendations. In the summer of 2013, the company rebranded as part of their expansion into K-12 and neighborhood data and ratings, Tressler said.

Although public schools are required to report data to state agencies, the same information about private schools isn't as readily available. That helps Niche's report stand out, Tressler said.

"We're really trying to provide a comprehensive assessment for these schools," he said. "We try to combine a lot of different aspects of the school experience."

For the private school study, Niche got most of its figures, including demographic data and student to teacher ratios, from the National Center for Education Statistics, Tressler said. Niche also incorporated statistics from their own database. The study doesn't rank every private school in the state, Tressler said, but only analyzes those with enough students and survey respondents.

The study ranks each school based on multiple factors and a weighted system, though it's worth noting that some of Niche's data is self-reported or subjective.

The academics and students culture and diversity grade, which looks at the variety of backgrounds and ethnicities of the student body, are based on statistics and surveys. Overall school experience is based just on surveys.

Academics account for 60 percent of the ranking, culture and diversity is worth 30 percent and school experience surveys count for 10 percent. The study also gives schools a rating for subsections, such as educational outcomes and teachers.

To find students, parents and alumni to take the surveys, Niche reached out to those who had already used the company's college database, Tressler said. Students directly reported SAT and ACT scores to Niche, he said. The type of colleges students are interested in or go onto attend, according to information from Niche users, also factored into the academic ranking.

Surveys are based on opinions about extracurricular activities, teachers, athletics and other elements. Of those who took the surveys, Tressler estimates 45 percent were current students, 40 percent were alumni, and another 10 to 15 percent were parents.

Tressler said to the company takes a comprehensive approach to each school and watches for red flags to account for self-reporting and a small sample sizes.

Niche gave Oregon Episcopal School, a preK-12 program with an enrollment of about 870, an A+ rating for academics, with students averaging a 2040 on the SATs, compared to the nationwide average of 1750. Oregon Episcopal School got an A rating for student culture and diversity- 53 percent of the student body is white, according to Niche. Tuition for high school students who don't live on campus is $28,000 for the 2014-2015 school year, according to the school's website.

According to Mo Copeland, OES Head of School, administrators had just learned of the Niche ranking. She said the school was proud given that the ranking was based on data, educational outcomes and input from students and parents.

"These measures show that we are delivering on our vision to 'connect people, ideas, and cultures to advance knowledge, create solutions, and enhance meaning'," she said in an email. "When we receive high marks from the OES community of students and parents, we have reason to be proud."

At St. Mary's Academy, an all-girls school at Southwest Fifth Avenue and Southwest Market Street, the average GPA is 3.5 to 4.0, according to Niche. There's a 14:1 student to teacher ratio, and 73 percent of students are white. According to the school's webpage, tuition is $12,750 for this school year. Enrollment is at about 700 students.

Principal Kelli Clark, in her second year, said the 150-year-old school has plans for expansion following a 2013 purchase of a former post office site, and thinks the school's academics is its top selling point.

"This is thrilling. This ranking really affirms that we're headed in the right direction and our community has a lot of confidence," Clark said. "We're very very proud of the program that we have here and to have it affirmed by our students and parents is just such an honor."

According to Niche, average test scores at Catlin Gabel School are 2040 for the SATs and 31 for the ACT. The school has 308 high school students, and tuition is $26,900 a year.

Tim Bazemore, Catlin Gabel head of school, said they appreciated the recognition, but overall believes that "school rankings are inherently flawed."

"The best way for families to assess the quality of schools and make choices is to personally explore the many diverse alternatives for education in our community," he said in an email. "We encourage families and students to research schools by reading their materials, speaking to families involved with the various schools, and visiting the schools to see for themselves what each school has to offer."

In the most diverse private high school rankings, De La Salle North Catholic High School in Portland was ranked fourth in the nation. Of the total student body, 36 percent are white, 34 percent are African American, 20 percent are Hispanic, and 4 percent are Asian, according to Niche's data.

Niche has also released data on K-12 public schools. Out of Oregon high schools, Riverdale High School in Portland got the top ranking.